Heretofore conventional automotive motor power plants employing electric motors and battery packs for driving a transmission for a limited range of travel of the vehicle are limited by the number and capacity of the storage batteries for traveling distances between 50 to 200 miles, approximately. Heretofore efforts have been made of providing alternate power sources for these power plants wherein a piston type reciprocating internal combustion engine was connectable into the power train with a generator for recharging the batteries and for providing a direct drive to the transmission and wherein various control mechanisms were employed for independent or joint operation of the two power sources.